Simultaneous photo-induced polymerization and surface modification by microfluidic spinning to produce functionalized polymer microfibers: the effect of their surface modification on cell adhesion

Functionalized polymer fibers were prepared by microfluidic spinning involving simultaneous photopolymerization and surface modification. A capillary-based microfluidic device was used with two miscible coaxially co-flowing phases to afford polymer fibers by the photopolymerization of poly(ethylene glycol) diacrylate present in the core phase and the surface modification of the fibers thanks to the presence of molecules (i.e., thiol and amine groups) reactive towards acrylate groups in the sheath phase. The use of molecules with higher functionality in thiol groups or higher concentration of these molecules increased the number of functional groups present at the surface of the fibers, while an increase of the flow rate of the sheath phase decreased it. The modification of the surface properties of the fibers was demonstrated by contact angle measurements showing differences in wetting properties and by incubation with RAW264.7 macrophages exhibiting a significant increase in cell adhesion for the thiol-modified microfibers.